A typical test work station consists of a computer-controlled test system, on the front or upper side of which, depending on the test system manufacturer, adapters specific to the test specimen can be docked. The main task of the adapters is to accurately position test specimens in order to press in a positionally correct manner a consequently large amount of electrical spring contacts onto the test specimen with simultaneous generation of counterforces by means of what are known as hold-down devices in order to prevent inadmissible bending of the test specimens. The necessary forces are generated either by mechanical lever action when closing the adapter hood or by means of vacuum application. Commercially available adapters have an upwardly opening hood, which is used to receive hold-down devices and possibly additional spring contacts, and also, in the case of vacuum adapters, to additionally seal the adapter in an air-tight manner.
Test work stations are used to test a specific printed circuit board, once it has been placed onto or into the test device, for faults in the conducting track routing, solder faults and component faults. Entire circuit blocks (clusters) can also be tested. The most well-known test methods for electronic modules of printed circuit board assemblies include the in-circuit test (ICT) and the function test (FCT). Here, test points and component pins provided on the printed circuit board assemblies are contacted directly in the test device with spring contact pins or rigid nails and can then be measured.
Test work stations are increasingly no longer combined in an organizational and spatial manner in what are known as test fields, but are integrated into production lines arranged in a U-shaped manner. For reasons of flexibility, these lines are not linked together by automatic transport systems.
In contrast to conventional assembly lines, workers do not remain at a work station at which they are supplied with parts individually or collectively in containers for processing, but rotate within a partial operating sequence or even the entire line and transport the parts. Ideally, the individual operations operate in a fully automated manner. Part deposit positions exist, ideally arranged one above the other, in order to keep the work stations narrow for the purpose of providing the shortest possible routes for the workers. One position is used only for intermediate storage of a finished part until the worker picks it up immediately once he has placed a part to be processed into the second position. The worker does not wait, but proceeds with the removed part to the next work station. When the worker next approaches the work station, if the processing of the part last inserted is finished, the processing position is free again. This cycle repeats itself.
Conventional test work stations or adapter thereof do not function ideally in the above sense. A first module brought from the previous work station first has to be deposited on a first deposit station next to the adapter. Once the adapter is opened, the tested module is removed and deposited on a second deposit station. The first module is then collected from the first deposit station and is placed into the adapter. The test procedure is started with the closure of the adapter hood and the worker takes the second module from the second deposit station and proceeds to the next work station.